Carbon nanotubes have been synthesized by using granular carriers (hereinafter called “particulate carriers”). Carbon nanotubes are synthesized using particulate carriers in the following manner. A catalyst for carbon nanotube synthesis is deposited on particulate carriers. The catalyst for carbon nanotube synthesis is then reduced by heating with a reducing gas, such as hydrogen, to be fine-grained. In doing so, the granular catalyst for carbon nanotube synthesis is supported by the particulate carriers. Subsequently, a source gas for carbon nanotubes is flown over the catalyst for carbon nanotube synthesis, whereby carbon nanotubes are synthesized.
In such a method for synthesizing carbon nanotubes, a technique to deposit a catalyst for carbon nanotube synthesis on particulate carriers is important. As techniques to deposit a catalyst for carbon nanotube synthesis on particulate carriers, chemical vapor deposition (CVD) (see Patent Literature 1, for example) and sputtering (see Non Patent Literature 1, for example) have been known.